2021 Lambers The pervasive use of P2O5 K2O CaO MgO and other molecules that do not exist in soil
If some fertiliser manufacturers wish to retain the outdated practice of labelling their product to include phosphorus, calcium, magnesium and potassium attached to oxygen that are not really in the fertiliser bag, then that is, literally, their business, but we would like to see them and especially FAO and EU update their nomenclature. In academic writing, the use of P2O5, CaO, K2O and MgO must really stop. We have moved on since Berzelius (1814) and von Liebig (1855). It is high time we acted upon Geoffrey Leeper’s advice (Leeper, 1948), and used chemical formulas that belong in the 21st century, rather than the 1800s.